1. Field of the Invention
This invention relates to a charging member used for contact charging in electrophotographic apparatus.
2. Description of the Related Art
A charging member provided in contact with an electrophotographic photosensitive member to charge the electrophotographic photosensitive member electrostatically is commonly so constituted as to have an elastic layer containing a rubber, in order to sufficiently and uniformly secure a contact nip between the electrophotographic photosensitive member and the charging member. In such an elastic layer, a low-molecular weight component is inevitably contained, and hence the low-molecular weight component may exude to the surface of the charging member as a result of long-term service to contaminate the surface of the electrophotographic photosensitive member. To cope with such a problem, Japanese Patent Application Laid-Open No. 2001-173641 discloses the constitution that the elastic layer is covered on its periphery with an organic-inorganic hybrid film so as to keep the low-molecular weight component from exuding to the surface of the charging member.